Methand - a better question to ask is: 'are there any bad regulators out there?'. If you buy a decent balanced reg from any major manufacturer its going to be fine.
Yes - there are small differences in ease of work on machine tests between units that are used by advertising execs and magazines to sell their product. Atomics, Apeks and, previously, Scubapro, were the darlings/sponsors of many a magazine article and market themselves at the premium choice very well. Poseidon also have a dedicated following.
But in terms of a noticeable differences while diving - you need something that will smoothly deliver to two divers overbreathing off the same first stage at depth, and any top line reg from any manufacturer will be able to handle this.
Get something that the LDS’s in your area can carry and can service. Don’t worry too much about the brand.
If you want to do something unusual such as ice diving then some regs are better than others when it comes to not free flowing. However for normal diving then any normal reg will work: I've dived with guys using home-brand el cheapo regs that breathed just fine at 200 feet.
Cheers,
Rohan.